The purpose of this study was to determine the effect of hierarchical goal structure of a yet-to-be performed task on gait and eye fixation behavior while walking to the location of where the task was to be performed. Subjects performed different goal-directed tasks representing three hierarchical levels of planning. The first level of planning consisted of having the subject walk to a bookcase on which an object (a cup) was located in the middle of a shelf. The second level of planning consisted of walking to the bookcase and picking up the cup which was in the middle, on the right side, or on the left side of the bookcase shelf. The third level of planning consisted of walking to the bookcase, picking up the cup which was located in the middle of the bookcase shelf, and moving it to a higher shelf. Findings showed that hierarchal goals do affect center of mass velocity and eye fixation behavior. Center of mass velocity to the bookcase increased with an increase in the number of goals. Subjects decreased gait velocity as they approached the bookcase and adjusted their last steps to accommodate picking up the cup. The findings also demonstrated the important role of vision in controlling gait velocity in goal-directed tasks. Eye fixation duration was more important than the number of eye fixations in controlling gait velocity. Thus, the amount of information gained through object fixation duration is of greater importance than the number of fixations on the object for effective goal achievement.

这项研究的目的是确定要执行的任务的层次目标结构对步态和眼睛注视行为的影响，同时步行到要执行任务的位置。受试者执行了不同的以目标为导向的任务，这些任务代表了计划的三个层次。计划的第一级包括让对象走到一个书架上，书架上放置了一个对象（杯子）。第二层计划包括步行到书架并拿起位于书架搁板中间，右侧或左侧的杯子。第三级计划包括步行到书架，拿起位于书架搁板中间的杯子，然后将其移到较高的搁架上。研究结果表明，分层目标确实会影响质心速度和注视行为。随着书目的数量的增加，书架的质心也随之增加。当受试者接近书架并调整其最后一步以适应拿起杯子时，他们的步态速度降低。这些发现还证明了视觉在控制目标任务中的步态速度中的重要作用。在控制步态速度方面，注视持续时间比注视眼睛的数量更为重要。因此，通过目标固定持续时间获得的信息量比有效目标实现时固定在目标上的数量更为重要。当受试者接近书架并调整其最后一步以适应拿起杯子时，他们的步态速度降低。这些发现还证明了视觉在控制目标任务中的步态速度中的重要作用。在控制步态速度方面，注视持续时间比注视眼睛的数量更为重要。因此，通过对象固定持续时间获得的信息量比为有效实现目标而固定在对象上的次数更为重要。当受试者接近书架并调整其最后一步以适应拿起杯子时，他们的步态速度降低。这些发现还证明了视觉在控制目标任务中的步态速度中的重要作用。在控制步态速度方面，注视持续时间比注视眼睛的数量更为重要。因此，通过目标固定持续时间获得的信息量比有效目标实现时固定在目标上的数量更为重要。